Generally, when the current head mounted display device is applied to virtual reality, the image frames of display panel of the head mounted display device are projected to user's eyes through an optical system, so that a virtual image is formed in the user's eyes. With the rapid development of technology, head mounted display device has been widely used in some specific areas of recreational, driving and medical. Amblyopic patients or people wearing artificial retina watch screen images through wearing the head mounted display device.
Head mounted display device has two important specifications: field of view (FOV) which indicates a range allowing a user to watch an image and an eye relief which indicates a distance between the head mounted display device and the user's eyes. However, according to the current design structure of head mounted display device, the field of view is ranged between 100-110 degrees. The limited field of view is due to that the size of the lens in the optical system head mounted display device increases with the field of view; and as a result, the weight and component size of the head mounted display device increase. Further, the eye relief between the lens in the optical system and the user's eyes also increase with the field of view; as a result, a larger lens is required and the weight and component size of the head mounted display device increase. Therefore, it is quite important to overcome the aforementioned issues.
The information disclosed in this “BACKGROUND OF THE INVENTION” section is only for enhancement understanding of the background of the invention and therefore it may contain information that does not form the prior art that is already known to a person of ordinary skill in the art. Furthermore, the information disclosed in this “BACKGROUND OF THE INVENTION” section does not mean that one or more problems to be solved by one or more embodiments of the invention were acknowledged by a person of ordinary skill in the art.